MONDAY, Sept. 16 (HealthDay News) -- Black Americans are more likely to develop high blood pressure than whites, and now a large new study has pinpointed four common genetic variations affecting their risk.

The study included nearly 30,000 black Americans at 19 sites across the United States and is the largest study to look at how genes influence blood pressure in black people, according to the researchers.

The investigators pointed out that most gene discoveries to date have been in white people and noted that previous studies in blacks failed to identify any genes associated with blood pressure.

Genes account for 40 percent to 50 percent of a person's risk for high blood pressure (hypertension). The four genetic variations identified in this study also affect other racial/ethnic groups, the researchers noted. Other risk factors for high blood pressure include lifestyle, diet and obesity.

The study also confirmed the role of other genes in increasing the risk of high blood pressure.

"In addition to their disproportionate suffering, hypertension occurs earlier in life for African Americans compared to individuals of other ancestries," study co-senior author Xiaofeng Zhu, a professor of epidemiology and biostatistics at Case Western Reserve University, said in a university news release. "Therefore, it is important to study this population to better understand genetic susceptibility to hypertension."

The findings were published recently in the American Journal of Human Genetics.

"Although it is unknown how the genes regulate blood pressure, our findings contribute to better understanding of blood pressure pathways that can lead to future development of drug target for hypertension and may guide therapy for clinical care," Zhu added.

Study co-senior author and geneticist Brendan Keating, of the Center for Applied Genomics at the Children's Hospital of Philadelphia, noted that "the research findings do not have immediate implications for treatment, but the hope is that discovering genes associated with disease risks will bring scientists closer to biological pathways and may suggest useful targets for new treatments." Keating is also with the department of pediatrics at the University of Pennsylvania.